package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.extension.conditions.query.QueryChainWrapper;
import com.hmdp.dto.Result;
import com.hmdp.entity.SeckillVoucher;
import com.hmdp.entity.Voucher;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherMapper;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IShopService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IVoucherService;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.SimpleRedisLock;
import com.hmdp.utils.UserHolder;
import lombok.extern.slf4j.Slf4j;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.connection.stream.*;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.time.Duration;
import java.time.LocalDateTime;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Slf4j
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {

    @Resource
    private ISeckillVoucherService seckillVoucherService;
    @Resource
    private RedisIdWorker redisIdWorker;
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Resource
    private RedissonClient redissonClient;
    @Resource
    private IVoucherService voucherService;
    @Resource
    private IShopService shopService;
    private static final DefaultRedisScript<Long> SECKILLL_SCRIPT;
    //初始化代理对象
    private IVoucherOrderService proxy;
    static {
        SECKILLL_SCRIPT = new DefaultRedisScript<Long>();
        SECKILLL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
        SECKILLL_SCRIPT.setResultType(Long.class);
    }

    private static final ExecutorService SECKILL_ORDER_EXECUTOR = Executors.newSingleThreadExecutor();

    @PostConstruct
    private void init(){
        SECKILL_ORDER_EXECUTOR.submit(new VoucherOrderHandler());
    }

    private class VoucherOrderHandler implements Runnable{

        String queueName = "stream.orders";
        @Override
        public void run() {
            while (true){
                //1. 获取消息队列中的订单信息
                try {
                    // 1. 获取消息队列中的订单信息 XREADGROUP GROUP g1 c1 COUNT 1 BLOCK 2000 STREAM stream.order >
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1).block(Duration.ofSeconds(2)),
                            StreamOffset.create(queueName, ReadOffset.lastConsumed())
                    );
                    // 2. 判断消息获取是否成功
                    if (list == null || list.isEmpty()){
                        // 2.1. 如果获取失败，说明没有消息，继续下一次循环
                        continue;
                    }
                    // 3. 解析消息中的订单信息
                    MapRecord<String, Object, Object> record = list.get(0);
                    Map<Object, Object> values = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(values, new VoucherOrder(), true);
                    // 4. 如果获取成功，可以下单
                    handleVoucherOrder(voucherOrder);
                    // 5. ACK确认 SACK stream.orders g1 id
                    stringRedisTemplate.opsForStream().acknowledge(queueName,"g1",record.getId());
                } catch (Exception e) {
                    log.error("处理订单异常",e);
                    handlePendingList();
                }
            }
        }

        private void handlePendingList() {
            while (true){
                //1. 获取消息队列中的订单信息
                try {
                    // 1. 获取Pending-List中的订单信息 XREADGROUP GROUP g1 c1 COUNT 1 BLOCK 2000 STREAM stream.order 0
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1),
                            StreamOffset.create(queueName, ReadOffset.from("0"))
                    );
                    // 2. 判断消息获取是否成功
                    if (list == null || list.isEmpty()){
                        // 2.1. 如果获取失败，说明Pending-List中没有消息，结束循环
                        break;
                    }
                    // 3. 解析消息中的订单信息
                    MapRecord<String, Object, Object> record = list.get(0);
                    Map<Object, Object> values = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(values, new VoucherOrder(), true);
                    // 4. 如果获取成功，可以下单
                    handleVoucherOrder(voucherOrder);
                    // 5. ACK确认 SACK stream.orders g1 id
                    stringRedisTemplate.opsForStream().acknowledge(queueName,"g1",record.getId());
                } catch (Exception e) {
                    log.error("处理Pending-List异常",e);
                    try {
                        Thread.sleep(20);
                    } catch (InterruptedException ex) {
                        ex.printStackTrace();
                    }
                }

            }
        }
    }
//    private BlockingQueue<VoucherOrder> orderTasks = new ArrayBlockingQueue<>(1024 * 1024);
//    private class VoucherOrderHandler implements Runnable{
//
//        @Override
//        public void run() {
//            while (true){
//                //1. 获取队列中的订单信息
//                try {
//                    VoucherOrder voucherOrder = orderTasks.take();
//                    //2. 创建订单
//                    handleVoucherOrder(voucherOrder);
//                } catch (Exception e) {
//                    log.error("处理订单异常",e);
//                }
//
//            }
//        }
//    }
//
//
    private void handleVoucherOrder(VoucherOrder voucherOrder){
        //获取用户
        Long userId = voucherOrder.getUserId();
        //创建锁对象
        RLock lock = redissonClient.getLock("lock:order:" + userId);
        boolean isLock = lock.tryLock();
        //判断是否成功获取锁
        if (!isLock){
            //没有获取到锁,报错或重试
            log.error("不允许重复下单");
            return ;
        }
        try {
            proxy.createVoucherOrder(voucherOrder);
        } finally {
            //释放锁
            lock.unlock();
        }
    }
    @Override
    public Result seckillVoucher(Long voucherId) {
        //获取用户
        Long userId = UserHolder.getUser().getId();
        Long orderId = redisIdWorker.nextId("order");
        // 1. 执行lua脚本
        Long result = stringRedisTemplate.execute(
                SECKILLL_SCRIPT
                , Collections.emptyList()
                , voucherId.toString()
                , userId.toString()
                , orderId.toString()
        );
        // TODO 暂时未实现刷新
        //从数据库查未对应优惠券库存并刷新
        Voucher voucher = voucherService.getById(voucherId);
        Long shopId = voucher.getShopId();
        shopService.queryById(shopId);
        voucherService.queryVoucherOfShop(shopId);
        // 2. 判断结果是否为0
        int r = result.intValue();
        if (r != 0){
            // 2.1. 不为0,代表没有购买资格
            return Result.fail(r == 1 ? "库存不足":"不可重复下单");
        }
        //3. 获取代理对象
        proxy = (IVoucherOrderService) AopContext.currentProxy();
        //4. 返回订单id
        return Result.ok(orderId);
    }
//    @Override
//    public Result seckillVoucher(Long voucherId) {
//        //获取用户
//        Long userId = UserHolder.getUser().getId();
//        // 1. 执行lua脚本
//        Long result = stringRedisTemplate.execute(
//                SECKILLL_SCRIPT
//                , Collections.emptyList()
//                , voucherId.toString(), userId.toString()
//        );
//        // 2. 判断结果是否为0
//        int r = result.intValue();
//        if (r != 0){
//            // 2.1. 不为0,代表没有购买资格
//            return Result.fail(r == 1 ? "库存不足":"不可重复下单");
//        }
//        // 2.2. 为0,把下单信息保存到阻塞队列
//        //2.3.创建订单
//        VoucherOrder voucherOrder = new VoucherOrder();
//        //2.4.订单id
//        Long orderId = redisIdWorker.nextId("order");
//        voucherOrder.setId(orderId);
//        //2.5.用户id
//        voucherOrder.setUserId(userId);
//        //2.6.优惠券id
//        voucherOrder.setVoucherId(voucherId);
//        //2.7. 放入阻塞队列
//        orderTasks.add(voucherOrder);
//        //3. 获取代理对象
//        proxy = (IVoucherOrderService) AopContext.currentProxy();
//        //4. 返回订单id
//        return Result.ok(orderId);
//    }
//    @Override
//    @Transactional
//    public Result seckillVoucher(Long voucherId) {
//        //1.查询优惠券
//        SeckillVoucher voucher = seckillVoucherService.getById(voucherId);
//        //2.判断秒杀是否开始
//        boolean begin = LocalDateTime.now().isAfter(voucher.getBeginTime());
//        boolean end = LocalDateTime.now().isBefore(voucher.getEndTime());
//        //2.3.未开始,返回异常
//        if (!(begin && end)){
//            return Result.fail("不在秒杀时间内!");
//        }
//        //3.已开始,判断库存是否充足
//        Integer stock = voucher.getStock();
//        //3.1不充足,返回异常
//        if (stock < 1){
//            return Result.fail("库存不足!");
//        }
//
//        Long userId = UserHolder.getUser().getId();
//        //创建锁对象
//        //SimpleRedisLock simpleRedisLock = new SimpleRedisLock("order:" + userId,stringRedisTemplate);
//        RLock lock = redissonClient.getLock("lock:order:" + userId);
//        boolean isLock = lock.tryLock();
//        //判断是否成功获取锁
//        if (!isLock){
//            //没有获取到锁,报错或重试
//            return Result.fail("获取锁失败");
//        }
//        try {
//            //获取代理对象(事务)
//            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
//            return proxy.createVoucherOrder(voucherId);
//        } finally {
//            //释放锁
//            lock.unlock();
//        }
//
//    }

    @Transactional
    public void createVoucherOrder(VoucherOrder voucherOrder) {
        //4.一人一单
        Long userId = voucherOrder.getUserId();
        //4.1查询订单
        Integer count = query().eq("user_id", userId).eq("voucher_id", voucherOrder.getVoucherId()).count();
        //4.2判断是否存在
        if (count > 0){
            log.error("用户已购买过一次!");
            return ;
        }
        //4.充足,扣减库存
        boolean success = seckillVoucherService.update()
                .setSql("stock = stock - 1")
                .eq("voucher_id", voucherOrder.getVoucherId())
                .gt("stock", 0)
                .update();
        if (!success){
            //扣减失败
            log.error("库存不足!");
            return;
        }
        //5.创建订单
        save(voucherOrder);
//        VoucherOrder voucherOrder = new VoucherOrder();
//        //订单id
//        Long orderId = redisIdWorker.nextId("order");
//        voucherOrder.setId(orderId);
//        //用户id
//        voucherOrder.setUserId(userId);
//        //优惠券id
//        voucherOrder.setVoucherId(voucherId);
//        save(voucherOrder);
//        //6.返回订单id
//        return Result.ok(orderId);
    }
}
